The present invention relates to a dynamic bearing device (fluid dynamic bearing device) for supporting a rotating member in a non-contact manner by dynamic pressure action of lubricating oil generated in a bearing gap. The bearing device is suitable for spindle motors of information equipment, for example, magnetic disk devices such as HDD and FDD, optical disk devices such as CD-ROM, CD-R/RW, and DVD-ROM/RAM, magneto-optical disk devices such as MD and MO, polygon scanner motors of laser beam printers (LBP), DLP (Digital Light Processing) projector and electrical apparatuses such as axial flow fans for small motors.